From mboxrd@z Thu Jan 1 00:00:00 1970 From: Przemyslaw Marczak Date: Wed, 26 Aug 2015 16:12:26 +0200 Subject: [U-Boot] DWMMC crontroller in Exynos4412 In-Reply-To: <55DDC1B6.2030603@uclv.cu> References: <55DCBD93.5050404@uclv.cu> <55DD5B63.4040108@samsung.com> <55DD6282.5090607@samsung.com> <55DDC1B6.2030603@uclv.cu> Message-ID: <55DDC94A.2090302@samsung.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Humberto, On 08/26/2015 03:40 PM, Humberto L?pez Le?n wrote: > Hi community, > > thank you all for answering my questions. > > On 08/26/2015 02:53 AM, Przemyslaw Marczak wrote: >> Hi, >> >> On 08/26/2015 08:23 AM, Jaehoon Chung wrote: >>> On 08/26/2015 11:26 AM, Simon Glass wrote: >>>> +Samsung people >>>> >>>> Hi, >>>> >>>> On 25 August 2015 at 13:10, Humberto L?pez Le?n >>>> wrote: >>>>> Hi Simon, >>>>> I'm working on implementing a driver for SD/MMC cards in the framework >>>>> GenodeOS. I think you could help me with your experience in this >>>>> type of >>>>> implementation in the u-boot. >>>>> The hardware platform on which the driver will work is a ODROID-x2 >>>>> (exynos4412). I use the DWMMC contoller, but I'm not sure if this >>>>> is the >>>>> right controller to handle SD/MMC cards in Exynos4412 SoC. The SDHCI >>>>> controller is most appropriate? >>> >>> If you're using exynos4412 board, you can choose sdhci or dwmmc >>> controller for eMMC, not SD/SDIO. >>> And in my experiment, dwmmc controller is more appropriate than >>> sdhci.(ex, performance) >>> >> >> It depends which mmc channel is used. In Exynos4412, there are 5 >> channels, but some channel configurations shares GPIO pins: >> - MMC0 - sdhci >> - MMC1 - sdhci, or MMC0 8-bit >> - MMC2 - sdhci - Odroid SD card, 4-bit mode >> - MMC3 - sdhci - or MMC2 8-bit >> - MMC4 - dwmmc, uses MMC0 pins for 4-bit, and MMC0-1 for 8-bit mode >> >> Odroid is using MMC2(sdhci) and MMC0/4(sdhci or dwmmc). >> >> So for eMMC cards you can use the dwmmc, and as Jaehoon wrote it is >> recommended for the better performance, but for SD card you must use >> sdhci controller. > This information is valuable to me, but now I would help if you tell me > where I can find the code of SDHCI controller for the SD card of > Exynos4412 in U-boat 2015.04-rc2 for a implementationtation reference. I > was reviewing the file exynos_dw_mmc.c as reference of DWMMC driver, > but now I have no idea what the file where the SDHCI driver for the > exynos4412 is implemented. > > Thank you very much for your collaboration. > > > Please check those files: - drivers/mmc/s5p_sdhci.c - drivers/mmc/sdhci.c But, isn't the kernel a better reference for you? Best regards, -- Przemyslaw Marczak Samsung R&D Institute Poland Samsung Electronics p.marczak at samsung.com